Types of mutations + proofreading, etc. BIO 160

Point mutation

mutation in single nucleotide

Synonymous(silent) mutations

point mutation that doesnt effect corresponding amino acid

Nonsynonymous(missense) mutations

point mutation that causes amino acid replacement

Nonsense mutation

point mutation that creates premature stop codon; almost always harmful

Frameshift mutation

Non-multiple of 3 insertion or deletion that causes shift in reaqding frame of mRNQ; changing all following codons

Transposons

DNA sequence that can replicate and move from one location to another

SNP

Site in genome where base pair differs among population

Duplication

Chromosomal mutation where region of chromosome is present twice instead of once; usually less harmful than deletion

Deletion

Chromosomal mutation where region of chromosome is missing; can be OK if only one member of homologous chromosome has it

Duplication and Divergence

Chromosomal process of creating new genes by duplication followed by change in sequence over evolutionary time; can result in gene family

CNVs

differences among individuals in # of copies of region of chromosome

Tandem repeat

region of DNA where many identical copies of short sequence of nucleotides are next to one another

Inversion

Reversal in normal # of block of genes

Reciprocal translocation

when 2 non-homologous chromosomes exchange parts

Mismatch repair

mechanism for repairing nucleotide mismatches in newly replicated DNA

Base excision repair

Incorrect DNA base and its sugar are removed and resulting gap repaired

Nucleotide excision repair

Repair of multiple incorrect bases; like mismatch repair but over longer region